1 files changed, 30 insertions, 8 deletions

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 856c8a287523..e03a7e19c73b 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -86,6 +86,9 @@ LIST_HEAD(smack_rule_list);
 
 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
 
+const char *smack_cipso_option = SMACK_CIPSO_OPTION;
+
+
 #define SEQ_READ_FINISHED       1
 
 /*
@@ -565,6 +568,11 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
                 goto unlockedout;
         }
 
+        /* labels cannot begin with a '-' */
+        if (data[0] == '-') {
+                rc = -EINVAL;
+                goto unlockedout;
+        }
         data[count] = '\0';
         rule = data;
         /*
@@ -808,9 +816,18 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
         if (m > BEBITS)
                 return -EINVAL;
 
-        sp = smk_import(smack, 0);
-        if (sp == NULL)
-                return -EINVAL;
+        /* if smack begins with '-', its an option, don't import it */
+        if (smack[0] != '-') {
+                sp = smk_import(smack, 0);
+                if (sp == NULL)
+                        return -EINVAL;
+        } else {
+                /* check known options */
+                if (strcmp(smack, smack_cipso_option) == 0)
+                        sp = (char *)smack_cipso_option;
+                else
+                        return -EINVAL;
+        }
 
         for (temp_mask = 0; m > 0; m--) {
                 temp_mask |= mask_bits;
@@ -849,18 +866,23 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
                         smk_netlbladdr_insert(skp);
                 }
         } else {
-                rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
-                        &skp->smk_host.sin_addr, &skp->smk_mask,
-                        PF_INET, &audit_info);
+                /* we delete the unlabeled entry, only if the previous label
+                 * wasnt the special CIPSO option */
+                if (skp->smk_label != smack_cipso_option)
+                        rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
+                                        &skp->smk_host.sin_addr, &skp->smk_mask,
+                                        PF_INET, &audit_info);
+                else
+                        rc = 0;
                 skp->smk_label = sp;
         }
 
         /*
          * Now tell netlabel about the single label nature of
          * this host so that incoming packets get labeled.
+         * but only if we didn't get the special CIPSO option
          */
-
-        if (rc == 0)
+        if (rc == 0 && sp != smack_cipso_option)
                 rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
                         &skp->smk_host.sin_addr, &skp->smk_mask, PF_INET,
                         smack_to_secid(skp->smk_label), &audit_info);